Luminous pile



T. C. SMITH.

LUMINOUS PILE. APPLICATION FILED ocr. 12, 1920.

.AINVTENToR Twdqre C. ,Sme/f UNITED STATES PATENT OFFICE.

LUMINOUS PILE.

Specification of Letters Patent.

Patented Oct. 18, 1921.

Application filed October 12, 1920. Serial No. 416,545.

T 0 all w hom it may concern.'

Be it known that I, THnoDonn C. SMITH, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented new and useful Improvements in LuminousPiles, of which the following is a specication.

My invention relates to a luminous pile, and has for its object toprovide means for holdingV a self-luminous material such as radiumpowder in a dry state beneath a transparent member, said meanspreventing the displacement of the self-luminous material.

Another object of the invention is to provide a luminous pile fabricconsisting of a retaining member of suitable material.

Another object of the invention is to provide a luminous pile consistingof a retaining member of suitable material having a nap, a dryself-luminous material immeshed in the nap of the retaining member and atransparent member covering said self-luminous material and inV contactwith the nap of the retaining member, said retaining member whenflexible having a backing member for adding stiffness thereto.

A further object of the invention is to construct a luminous pendant ofthe pile fabric above referred to.

A still further object of the invention is to provide a luminous pilewhich consists of a. self-luminous powder sprinkled upon a materialhaving` a nap, such as felt; matting or packing the self-luminousmaterial so it becomesimmeshed in the nap and a transparent memberplaced over the self-luminous powder so as vto engage the nap and causethe different elements thereof to entwine each other and the particlesof the self-luminous powder to prevent displacement of the latter.

With these ends in View, this invention consists in the details ofconstruction and combination of elements hereinafter set forth and thenspecifically designated by the claims.

In order that those skilled in the art to which this inventionappertains, may under-- stand how to make and use the same, I willdescribe its construction in detail, referring by numerals to theaccompanying drawing forming a part of this application, in which Figure1 is a Sid@ elevation of a pendant and a ball link chain to which it maybe fastened, portions being broken away and shown in section to:illustrate one form of producing the luminous pile.

Fig. 2 is a sectional view of a different formation of the luminouspile.

Fig. 3 is a face view of another formation.

Fig. 4 is a transverse sectional view thereof.

In the use of a self-luminous material the same is generally mixed withan adhesive and pasted or painted upon an object and it has been foundthe brightness of the material when so mixed is usually only twentyfiveper cent. of that of the dry material and the material when mixed withan adhesive also decreases in brightness at a much higher rate than doesthe dry material of the same brightness so that by using theself-luminous material in the dry state its highest efficiency may bemaintained and by the use of my invention I can provide a surface of theself-luminous material without the use of an adhesive or other liquidand element and can utilize the same in producing pendants designatingslides or signs, dial-faces for instruments and the hands and pointersof such instruments.

In Fig. 1, I have shown a pendant comprising a transparent facing 2 thesame being` in this particular case a cup shaped member of glass havingan external flange 3 andwithin this transparent face is located theretaining member 4 of some suitable materialV having a nap in which isimmeshed a self-luminousfmaterial 5 such as radiumV powder in its dryform, said powder being prevented from displacement by the entangling ofthe nap elements about one another and the particles of powder `withinthe retaining member 4 is forced into close proximity with thetransparent facing 2 by means of'a suitable backing member 6 such ascork or other suit-able solid or semi-solid object ory substance, whilethe top of the transparentface or the open end thereof is hermeticallysealed by a suitable layer of material 7 such as wax or paraffin.

To complete the pendant, I provide a dome or bell shaped metallic cap 8preferably of brass secured to the transparent facing by rolling orcrimping the edge thereof about the external flange 3. This cap isprovided with an opening 9 of slightly larger diameter than the balls 10of the ball chain to which the pendant is adapted to be attached 2 A y j1,394,449

From this opening leads a slot 11 to the top ot' the cap, said slotbeing of suiiicient lwidth to accommodate one of the wire links 12 ot'the chain so that to place the pendant upon the chain it is onlynecessary to insert the end ball of the chain through the opening 9 andbring the wire link 12 into registration with the slot 11 and vmovingsaid link through said slot until it assumes the position hereinillustrated after which the material'ot' the cap at each side of theslot may be pinched y or forced inward so that the major portion of saidslot or that part unoccupied by the link will be of smaller width thanthe diameter or thickness of the. wire link which will preventaccidental with-V drawal of the link from said Slot thus fastening thependant to the chain.

When the luminous pile herein described is used with pendants of thischaracter the life of the pendant will be much longer and the brightnessmuch greater so as to be discernible at greater' distances and wheresaid pendants are used to designate positions ot pull chains on electriclight fixtures and the like such pull chains may be readily located inthe darkness.

In Fig. 2, lhave shown the luminous pile consisting of a hacker orbacking member 13 disposed across the retaining member 1d at least oneface or" which is provided with a nap for holding the self-luminousmaterial or powder 15, while across the retaining` member with thepowder immeshed is a transparent member 16, all of said members beingheld together by some suitable clamping means 17 here shown as forming apart of the backing member with one edge crimped or rolled over thetransparent member.V rllhe transparent member may be oi glass orCelluloid and when the luminous pile is made in this form it may beutilized as a Vdial face for instruments such as those used by naval andmilitary otlicersas well as time pieces `or it may be used as a sign orVdesgnating slide such as are used in apartmeA t houses or the like forindicating cer- `tai mail boxes or bells, the information desired to beimparted being written across the transparent member.

In Figs. 3 and 4, I have shownfa slightly der 2O therebetween arefastened together along their edges as by stitches 21.

As above stated the self-luminous material such as radium or otherpowders having a radioactive constituent can be used in its dry V stateand without mixing it with some 'other element that reduces theradiation of suc-h materials and thev life of such materials isprolonged and the brightness retained, and l have found that byproducing a luminous pile as above described l obtain all the advantagesof all the luminous material in its dry state.

Although T. have described my invention as embodying the retainingmember such as ielt having a `nap it is to be readily under'- stood thatother materials may be used hav'- ing a inely divided surface for theretention or" the powder particles some of such other materials beingcrape paper the fibers of which produce a nap, while thecellularisurtace would also retain some of the particles; strawboard onwhich a nap hasbeen raised by finely cutting the surface or any clothhaving a rough surface, and it is to be understood that where l refer toa nap it re lates to any surface which will retain powder particlesparticularly when held in close proximity to a transparent member.

f course I do not wish to be limited to the exact details ofconstruction as herein shown* as these may be varied within the limitsof the appended claims without departing Jfrom the spirit of myinvention.

Having thus ullydescribed my invention,

'what l claim as new vand useful is ztransparent member, a retainingmember having a nap ldisposedwithin the transpar- -ent member, aselfduminous materialV in a dry orpowdered state immeshed in said napand disposed against the transparent member, abacking member for holdingthe retaining .member'against vthe transparent member, and means forhermetically sealing the aforementioned parts.

1n testimony whereof, I have hereunto aiiixed myV signature.

rnnononn c. SMITH.

